struct Tree {
    tree_type treetype;
    int treesize;
    char* value;
    Tree* tree;
    Tree () {
        this->treesize = 0;
        this->value = 0;
        this->tree = 0;
    }
};

void ParseAssigment (Tree& tree) {
    std::queue<Token> Postfix; // В нем хранится постфикс выражение например [1][2][3][*][+]
    std::stack<Tree> postfixTree;
    while (!Postfix.empty()) {
        if (Postfix.front().tokentype == token_type_numeric) {
            Tree* nodeTree = new Tree;
            nodeTree->treetype = tree_type_num_value;
            nodeTree->value = Postfix.front().value;
            Tree* childTree = new Tree[2];
            nodeTree->tree = childTree;
            postfixTree.push(*nodeTree);
        }
        else if (isOperator(Postfix.front().tokentype)){
            Tree* nodeTree = new Tree;
            nodeTree->treetype = tree_type_operator;
            nodeTree->value = strOperator(Postfix.front().tokentype);
            nodeTree->treesize = 2;
            Tree* childTree = new Tree[2];
            nodeTree->tree = childTree;
            nodeTree->tree[1] = postfixTree.top();
            postfixTree.pop();
            nodeTree->tree[0] = postfixTree.top();
            postfixTree.pop();
            postfixTree.push(*nodeTree);
        }
        Postfix.pop();
    }
    tree.treetype = tree_type_postfixexpr;
    tree.tree = &postfixTree.top();
    postfixTree.pop();
    std::cout << "[" << tree.tree->tree[1].value << "]\n"; // Тут все значения корректны... т.е. показывает * как и должно быть, с остальными тоже все ок
}

#include "tree.cpp"

int main () {
    Tree* tree = new Tree;
    ParseAssigment(*tree);
    std::cout << "outside func[tree->tree->treetype][" << tree->tree->tree[1].value << "]\n"; // вот тут пишет "Unhandled exception. Access violation..."
    return 0;
}

ParseAssigment(*tree);

struct Tree {
    tree_type treetype;
    int treesize;
    char* value;
    std::stack<Tree*> tree;
    Tree () {
        this->treesize = 0;
        this->value = 0;
        this->tree = 0;
    }
};

    Tree* tmp = new Tree;
    *tmp = postfixTree.top();
    tree.tree = tmp;

std::stack<Tree*> tree;